Android’s vulnerability is not something unfathomable. Despite, security researchers have finally discovered an effective way to hijack an Android phone remotely through a nearly four-year-old hacking technique known as ‘Rowhammer’. On Thursday, researchers from Vusec research group published a paper that unveils how the Rowhammer exploit, dubbed as GLitch, leverages embedded GPUs to remotely execute malicious code in Android phones.
GLitch is the very first example of remote Rowhammer exploit on ARM Android devices. The Rowhammer technique involves inducing electric leaks in memory (DRAM) which results in the flipping of individual bits in adjacent memory rows and thereby leaking content from them. This will make it easy for the attacker to remotely hack the smartphone without relying on a software tweak.
The technique gives the hacker more flexibility over previous methods that relied on CPUs. GLitch is the first Rowhammer attack that is based on Javascript, meaning it can be executed when a user does nothing more than visiting a malicious site.
GLitch gets its name as it uses WebGL programming interface for rendering graphics to trigger a known glitch in DDR3 and DDR4 memory chips, the reason behind the peculiar capitalization. The term Rowhammer was coined after hackers repeatedly accessed – or ‘hammered’ – specific rows of the memory chip and altered its data by changing ‘zeros’ to ‘one’, and vice-versa. This intended bit-flip gave them control of the system.
The researchers have shown their proof of concept attack that how GLitch loads a malicious javascript in the browser and remotely hacks the victim’s phone. And all this in less than 2 minutes. Though it can only run the malicious code within the privileges of the browser, meaning it can spy on user’s browsing habits or steal his credentials, but can’t gain deeper access to user’s Android phone. Currently, GLitch targets only the Firefox browser and smartphones running on Snapdragon 800 and 801 SoC. Although the exploit isn’t mature enough to have an immediate adverse effect on most end users, it works on Android phones like LG Nexus 5, HTC One M8 or LG G2.
Additionally, the researchers have said,” If you’re wondering if we can trigger bit flips on Chrome the answer is yes, we can. As a matter of fact, most of our research was carried out on Chrome. We then switched to Firefox for the exploit just because we had prior knowledge of the platform and found more documentation.”
That being said, Google replied that the attack isn’t a practical threat to the vast majority of users. Also, the search engine giant mitigated this remote vector in Chrome on March 13 and its team is working to implement protection on other browsers. Mozilla is also updating Firefox to prevent Rowhammer attacks. Furthermore, the recent DDR4 smartphone memories offer a safeguard that prevents electric leakage from changing their values.
